The boy fell and scraped the skin off his knee.

这男孩摔了一跤, 了膝盖上的皮。

I barked my shin on a tree stump.

我磕到了树桩上，胫部了皮。

He boohooed when he skinned his knee.

当他的膝盖, 他大声哭了起。

Jack skinned his knee when he fell.

跌倒膝盖了皮。

The bullet merely creased his shoulder.

子弹只不过了他肩部的皮肤。

He skinned his knees when fell.

他摔倒了膝部的皮肤。